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PubMed1989

Studies on a novel antitumor antibiotic, phenazinomycin: taxonomy, fermentation, isolation, and physicochemical and biological characteristics.

A new antibiotic, phenazinomycin (C27H32N2O, MW 400), was isolated from the cultural mycelium of Streptomyces sp. WK-2057. This antibiotic possesses antibacterial activities against Gram-positive bacteria in vitro, direct cytotoxic activities against HeLa S3, P388 and P388 doxorubicin-resistant cells in vitro and antitumor activities against experimental murine tumors in vivo.

Animals↗
PubMed1988

Neihumicin, a new cytotoxic antibiotic from Micromonospora neihuensis. I. The producing organism, fermentation, isolation and biological properties.

A new cytotoxic and antifungal antibiotic, neihumicin, was isolated from the culture broth of a soil isolate identified as Micromonospora neihuensis Wu, sp. nov. Neihumicin shows in vitro cytotoxicity against KB tissue culture cells (ED50 0.94 micrograms/ml) as well as antifungal activity against Saccharomyces cerevisiae ATCC 9763.

Antibiotics, Antineoplastic↗
PubMed2006

Levan (beta-2, 6-fructan), a major fraction of fermented soybean mucilage, displays immunostimulating properties via Toll-like receptor 4 signalling: induction of interleukin-12 production and suppression of T-helper type 2 response and immunoglobulin E production.

BACKGROUND: Products from the fermentation process of soybeans by Bacillus subtilis (natto) have been shown to possess anti-tumour and immunomodulatory activities. However, the formulations previously examined were not chemically pure, and this is a major limitation for elucidation of the molecular mechanisms for their activities. OBJECTIVE: In order to determine which components in soybean mucilage exert immunostimulatory activities, we examined the activities of their purified forms in vitro and in vivo in mice. METHODS: B. subtilis (natto) and fractions including levan and poly-gamma-glutamic acid (gamma-PGA) from fermented soybean mucilage were prepared. Levels of cytokine production by mouse macrophage cells after treatment with the fractions were measured by means of ELISA. In vivo effect of levan delivered intragastrically on ovalbumin (OVA)-specific T-helper type 2 (Th2) response with IgE production was examined in BALB/c mice that had been immunized intraperitoneally with OVA. Results Levan but neither gamma-PGA nor killed B. subtilis (natto) was found to exert strong activity to induce production of IL-12 p40 and TNF-alpha by macrophage cell lines in vitro. RESULTS: of experiments using Toll-like receptor (TLR) 4-deficient mice and TLR4-transfected human cell line indicated that TLR4 is involved in pattern recognition of levan. Oral administration of levan in vivo significantly reduced the serum levels of OVA-specific IgE and Th2 response to OVA in mice immunized with OVA. CONCLUSION: Levan is an immunostimulatory moiety in products from the fermentation process of B. subtilis (natto) and may be useful for prevention of allergic disorders with IgE production.

Adjuvants, Immunologic↗
PubMed1978

Taxonomic study and fermentation of producing organism and antimicrobial activity of mildiomycin.

A taxonomic study of strain B-98891, which produced an antibiotic effective against powdery mildew of barley, identified it as Streptoverticillium rimofaciens. On agar media the antibiotic, which was named mildiomycin, was only weakly active against most fungi and bacteria tested. However, it inhibited some Mycobacterium and Rhodotorula, and it showed excellent control of powdery mildew of barley plants in greenhouse tests at concentrations between 31.2 and 62.5 ppm. Rhodotorula rubra IFO 0907 was selected as the test organism for in vitro assay of mildiomycin.

Antifungal Agents↗
PubMed1983

U-56,407, a new antibiotic related to asukamycin: isolation and characterization.

U-56,407, a bright yellow, crystalline antibiotic was isolated from fermentations of Streptomyces hagronensis (strain 360). This antibiotic was extracted from fermentation broths with halogenated hydrocarbons and purified by silica gel chromatography and crystallization. U-56,407 is active in vitro against Gram-positive bacteria but not Gram-negative organisms. It failed to demonstrate in vivo activity in experimentally infected mice. Physical-chemical characterization of U-56,407 supports a molecular formula of C29H32N2O7 and a structure related to the antibiotic asukamycin.

Anti-Bacterial Agents↗
PubMed1998

Expression of active human tissue-type plasminogen activator in Escherichia coli.

The formation of native disulfide bonds in complex eukaryotic proteins expressed in Escherichia coli is extremely inefficient. Tissue plasminogen activator (tPA) is a very important thrombolytic agent with 17 disulfides, and despite numerous attempts, its expression in an active form in bacteria has not been reported. To achieve the production of active tPA in E. coli, we have investigated the effect of cooverexpressing native (DsbA and DsbC) or heterologous (rat and yeast protein disulfide isomerases) cysteine oxidoreductases in the bacterial periplasm. Coexpression of DsbC, an enzyme which catalyzes disulfide bond isomerization in the periplasm, was found to dramatically increase the formation of active tPA both in shake flasks and in fermentors. The active protein was purified with an overall yield of 25% by using three affinity steps with, in sequence, lysine-Sepharose, immobilized Erythrina caffra inhibitor, and Zn-Sepharose resins. After purification, approximately 180 microgram of tPA with a specific activity nearly identical to that of the authentic protein can be obtained per liter of culture in a high-cell-density fermentation. Thus, heterologous proteins as complex as tPA may be produced in an active form in bacteria in amounts suitable for structure-function studies. In addition, these results suggest the feasibility of commercial production of extremely complex proteins in E. coli without the need for in vitro refolding.

Cloning, Molecular↗
PubMed1969

Evaluation of a method of measuring fermentation rates and net growth of rumen microorganisms.

The method of el-Shazly and Hungate for measuring gas production in rumen contents was slightly modified and used throughout this investigation. The variation in the fermentation rates due to samples collected separately from a sheep fed on hay was less than 2%. When samples obtained through a stomach tube were compared with samples collected through the rumen fistula, the variation was about 3%. The rates of gas and acid production were approximately similar in samples obtained from the rumen at the same time when no sodium bicarbonate was added. During in vitro incubation of whole ruminal contents, there was a highly significant correlation between the net growth rate values (obtained by using fermentation capacity as an index) and the change in concentration of viable rumen bacteria or total ciliate protozoa.

Acids↗
PubMed1978

Toxicological studies on a new veterinary antibiotic turimycin.

Turimycin is a fermentation product ofStreptomyces hydroscopicus (DDR W-Patent-Nr. 84 450). It is highly active in vitro against a range of mycoplasma species and gram-positive bacteria. The acute toxicity was determined in mice, rats and dogs. In mice and rats LD50 values ranged from 750 mg/kg intraperitoneally to higher than 3000 mg/kg orally. In a chronic study on dogs oral doseas of 50 nad 125 mg/kg Turimycin were given daily in capsules for 12 months. The results showed no functional or morphological differences between treated and control animals.

Animals↗
PubMed1998

The scientific rediscovery of an ancient Chinese herbal medicine: Cordyceps sinensis: part I.

This review presents Cordyceps sinensis (Berk.) Sacc., a fungus highly valued in China as a tonic food and herbal medicine. The extant records show the continued use of C. sinensis is now centuries old. The major chemical, pharmacological, and toxicological studies on C. sinensis and the various derived, cultured, fermented mycelial products currently in use are reviewed from the English and Chinese literature. Preclinical in vitro and in vivo studies and clinical blinded or open-label trials in to date over 2000 patients are reviewed. These studies show the main activities of the fungus in oxygen-free radical scavenging, antisenescence, endocrine, hypolipidemic, antiatherosclerotic, and sexual function-restorative activities. The safety of the fungus, its effects on the nervous system, glucose metabolism, the respiratory, hepatic, cardiovascular, and immune systems, immunologic disease, inflammatory conditions, cancer, and diseases of the kidney will be reviewed in the second part of this article to be published in the winter issue of this journal.

Aged↗
PubMed1969

Prophylactic effects of gamma-aminobutyrylhistidine (homocarnosine) on experimental staphylococcal infections in mice.

Prophylactic administration of the dipeptide homocarnosine induced a high degree of resistance to staphylococcal infections in Swiss albino mice. It expressed its antistaphylococcal properties 1 hr after administration, and this protection lasted for at least 1 month. Although 5 mg per animal (approximately 200 to 250 mg/kg) was routinely used in our studies, experiments showed that comparable results could be obtained with 1.5 mg per animal. Rechallenge experiments indicated that an active infection by itself may confer immunity up to 4 weeks, but an infection after treatment with homocarnosine gave complete immunity to reinfection for at least 2 months. Studies in vitro showed that homocarnosine had no effect on the growth or certain other characteristics (ability to ferment mannitol, liquefy gelatin, and to produce coagulase, deoxyribonuclease, and pigment) of S. aureus. It appears that resistance induced by this peptide is an indirect effect mediated by some nonimmunological host reaction. The possible involvement of homocarnosine, among other compounds, in the protective action of deproteinized beef extract against staphylococcal infections is suggested.

Animals↗
PubMed1985

Inactivation of glycerol dehydrogenase of Klebsiella pneumoniae and the role of divalent cations.

Anaerobically induced NAD-linked glycerol dehydrogenase of Klebsiella pneumoniae for fermentative glycerol utilization was reported previously to be inactivated in the cell during oxidative metabolism. In vitro inactivation was observed in this study by incubating the purified enzyme in the presence of O2, Fe2+, and ascorbate or dihydroxyfumarate. It appears that O2 and the reducing agent formed H2O2 and that H2O2 reacted with Fe2+ to generate an activated species of oxygen which attacked the enzyme. The in vitro-oxidized enzyme, like the in vivo-inactivated enzyme, showed an increased Km for NAD (but not glycerol) and could no longer be activated by Mn2+ which increased the Vmax of the native enzyme but decreased its apparent affinity for NAD. Ethanol dehydrogenase and 1,3-propanediol oxidoreductase, two enzymes with anaerobic function, also lost activity when the cells were incubated aerobically with glucose. However, glucose 6-phosphate dehydrogenase (NADP-linked), isocitrate dehydrogenase, and malate dehydrogenase, expected to function both aerobically and anaerobically, were not inactivated. Thus, oxidative modification of proteins in vivo might provide a mechanism for regulating the activities of some anaerobic enzymes.

Cations, Divalent↗
PubMed1989

Cariological assessment of leucrose [D-glucopyranosyl-alpha(1----5)-D-fructopyranose] as a sugar substitute.

Leucrose [D-glucosyl-alpha(1----5)-D-fructopyranose] prepared by microbial-enzymatic transglycosidation from sucrose, is the first alpha(1----5)-linked disaccharide which possesses excellent nutritional properties with regard to metabolic utilization and is well tolerated. The aim of the present work was to assess its cariogenic potential. Yeast invertase was shown to be inhibited by leucrose in a noncompetitive way, while hydrogenated leucrose (leucritol) acted as an activator. Plaque polysaccharide forming glucosyltransferases from Streptococcus cricetus AHT were not influenced by leucrose, but by leucritol. Essentially no acid formation was observed after incubation of leucrose with suspensions of human dental plaque, S. mutans NCTC 10449, Lactobacillus casei LSB 132 and Actinomyces viscosus Ny 1 No. 30. Leucrose was a competitive inhibitor of the acid formation from sucrose by S. mutans NCTC 10449 at neutral pH. Furthermore, leucrose inhibited at neutral pH considerably the uptake of sucrose by S. mutans NCTC 10449. The uptake of fructose and maltose was also inhibited but that of glucose not at all. In Cara rats as the animal model, leucrose was compared to sucrose and to corn starch for its cariogenic potential. In sharp contrast to the group fed with 30% sucrose, caries scores of the 30% leucrose group were not significantly different from the starch group. pH telemetry with an indwelling electrode in man proved lueucrose to be 'safe for teeth' since plaque pH did not drop below pH 5.7. Leucrose is a novel noncariogenic disaccharide and thus represents a highly promising sugar substitute for caries prevention.

Actinomyces↗
PubMed2000

In vitro evaluation of intraluminal factors that may alter intestinal permeability in ponies with carbohydrate-induced laminitis.

OBJECTIVES: To study the in vitro effects of cecal contents incubated with corn starch on colonic permeability in horses. ANIMALS: 4 healthy adult ponies. PROCEDURE: Mucosal specimens were obtained from the right ventral colon and mounted in Ussing chambers. Changes in short circuit current, conductance, and large-molecule permeability in response to addition of cecal contents and cecal contents incubated with corn starch were evaluated for 120 minutes. RESULTS: Incubation of cecal contents with corn starch for 8 hours resulted in a decrease in cecal content pH and an increase in lactic acid concentration. These changes were similar to those reported in vivo for ponies given corn starch. Exposure of colonic mucosa to cecal contents incubated with corn starch resulted in an increase in tissue conductance and permeability of technetium Tc 99m pentetate, compared with mucosa exposed to cecal contents alone. CONCLUSIONS AND CLINICAL RELEVANCE: In vitro exposure of colonic mucosa to cecal contents incubated with starch resulted in increased paracellular permeability. Fermentation of excessive amounts of carbohydrate in the intestinal lumen of horses may directly induce increased intestinal permeability associated with carbohydrate-induced laminitis.

Animals↗
PubMed2000

Efficacy of laidlomycin propionate in low-protein diets fed to growing beef steers: effects on steer performance and ruminal nitrogen metabolism.

We conducted two experiments to evaluate the effect of the ionophore laidlomycin propionate (LP) on steer performance and ruminal N metabolism. Experiment 1 was a 91-d growth study evaluating the growth and ruminal characteristics of steer calves consuming supplemental LP. Steers (n = 96; 255 +/- 3 kg; four steers/pen; six pens/treatment) were used in a randomized complete block design with a 2 x 2 factorial arrangement of treatments consisting of two levels of dietary CP (formulated to be 10.5 and 12.5% of DM) with and without LP (11 mg/kg diet DM). Ruminal fluid was collected via stomach tube on d 91 from one steer randomly selected from each pen. No CP x LP interactions were observed with performance data (P > .64). Final weight and total gain were greater (P < .07) for 12.5% CP and LP compared with 10.5% CP and control steers, respectively. Also, DMI was increased (P = .08) with 12.5% CP but not with LP supplementation (P = .36). In addition, ADG and gain:feed ratio were greater (P < .03) for both 12.5% CP and supplemental LP. Ruminal NH3 N concentration was greater (P < .09) with 12.5% CP and LP. Total VFA concentration and molar proportion of acetate were not affected by treatment (P > .11). However, propionate concentration was increased (P < .09) with 12.5% CP and LP, and acetate:propionate was lower (P = .02) with LP supplementation. In Exp. 2, six steers were used in a replicated 3 x 3 Latin square design to compare ruminal fermentation and protein degradation in steers without ionophore feeding or adapted to LP or monensin. In vitro deamination of amino acids by adapted ruminal microbes was also assessed. Ionophore supplementation decreased (P = .07) ruminal NH3 N concentration compared with control steers, and LP increased (P = .02) ruminal NH3 N compared with monensin. Molar proportion of acetate was decreased (P = .02) and propionate increased (P = .01) with ionophore treatment. Consequently, ionophore supplementation depressed the acetate:propionate ratio (P = .01). In situ degradation rate of soybean meal (SBM) CP was greater (P = .09) with ionophore treatment, but estimates of SBM undegradable intake protein were not altered by treatment (P > .25). Microbial specific activity of net NH3 N release and alpha-amino N degradation were decreased (P < .04) with ionophores. Based on this study, LP and monensin did not affect the extent of ruminal degradation of SBM CP but decreased amino acid deamination.

Animal Feed↗
PubMed1990

Effect of culture medium on acid production from sorbitol by oral bacteria.

The fermentation of sorbitol or glucose and the acid production by strains belonging to the genera Actinomyces, Lactobacillus, and Streptococcus isolated from the predominant sorbitol-fermenting human dental plaque flora were studied in cultures in complex or defined bacteriologic broths and in saliva-based broth. The growth yields of Lactobacillus and Streptococcus in the saliva-based media and of Actinomyces in the defined broth were poor. Addition of fermentable carbohydrate to the saliva-based broth favored the growth of Streptococcus and Lactobacillus but not that of Actinomyces. The results showed obvious differences in the capacity of oral bacteria to ferment sorbitol between cultures in saliva-based and bacteriologic broths. Lactobacillus failed to utilize sorbitol when saliva was the only source of nutrients. Lower proportions of lactic and formic acids were formed from sorbitol by Actinomyces and Lactobacillus in the saliva-based than in the bacteriologic media. The findings illustrate some mechanisms possibly involved in the interactions between sorbitol and dental plaque flora.

Actinomyces↗